The present invention relates to forms for cement slabs and the like, for in situ molding a roof slab or intermediate floor slab.
Roof slabs, floor slabs as well as other flat horizontal parts of buildings can have any of a wide variety of sizes and shapes. It is for this reason that the forms originally conceived for moulding such slabs had to be versatile and therefore they were made up of narrow planks of wood secured one to another. The forms erected in this manner required the skill of a carpenter.
Modern building techniques rely on the use of large panels, which are supported in a horizontal position, for in situ moulding roof slabs or intermediate floor slabs, because each storey in a given building is merely a repetition of a previous storey. These panels replace the individual planks of wood which were secured together and to a vertical support so as to form a horizontal flat moulding surface onto which the cement was then poured.
The use of large panels has become widely spread in spite of their high cost because they afford the possibility of being used for moulding the floor slabs or roof slabs of a multiple storey building, without having to dismantle and assemble the wooden moulding structures floor by floor. Although these panels also have to be erected and brought down before and after each storey is cast, they are simple to operate thus reducing site personnel. These panels are generally made of metal and they are held in place by struts of variable length which are made to rest upon a previously moulded lower floor. Although these panels represent an advancement in the art, they are heavy and awkard and therefore they can only be mounted in place by an army of workmen or by the use of cranes.
It is the aim of the present invention to provide a form for moulding a roof slab or an intermediate floor slab, in situ, which is just as versatile as the original planks of wood but which is just as simple and easy to assemble as a large panel but which is lighter and easier to handle whereby the assembly of a form can be effected by one man, without skill and without the need of cranes. The simplified form which can be obtained by following the teachings of the present invention is basically for use in buildings of regular dimensions and shapes. In this connection, it is felt that the present invention is particularly useful for erecting groups of buildings or houses of uniform characteristics.
According to the present invention, the new form can be assembled by mounting it either on an already moulded or erected wall or on the form to be used to mould the walls of the enclosure.
For example, the form of the present invention can be used in combination with the form described in my copending patent application Ser. No. 676,613 filed on Apr. 13th., 1976 wherein I disclose a form for building walls and the like. In this case the walls and roof of an enclosure can be moulded or cast simultaneously.
The form of the present invention basically comprises a plurality of light, small interengaging panels of particular configuration and structure whereby the form is easier and faster to assemble than those known in the art because most of the forms are already provided with supports for neighbouring forms. The majority of the panels comprise means for supporting an adjacent panel whereby it is possible to build up a "chess-board array" extending over an enclosure and thereby defining a flat continuous moulding surface.
In use, and once the walls of an enclosure have been erected, or once the forms for such walls have been assembled, a panel of the form of the present invention is rested on means mounted to that effect on the walls or vertical forms defining the enclosure, whereafter a multiplicity of other panels are positioned one at a time in scale fashion over all the surface of the enclosure.
The first panel is positioned in one corner of the enclosure and the form is completed by adding the remaining panels until the diagonally opposite corner of the enclosure is reached. Each panel will rest on previously positioned panels, or, on a previously positioned panel and on the means mounted to that effect on the wall or vertical form defining the enclosure.
Although I have said that the form is assembled by positioning the first panel in the corner of an enclosure and resting it on means secured to that effect to the walls or the forms thereof, I have found it possible to place the first panel in any other position although in such case it is necessary to carefully determine such position so that the remaining panels cover the rest of the enclosure. Additionally it is necessary to provide further supports for the first panel because only the means on the walls or the vertical forms adjacent each corner of the enclosure can afford per se a stable support for a panel of the form of the present invention.
In essence, the present invention provides a form for slabs and the like, for moulding a roof or intermediate floor slab for a substantially rectangular enclosure, the form comprising a plurality of substantially rectangular panels each defining a flat substantially rectangular moulding surface, the panels being arranged in chess-board array to define a substantially flat continuous moulding surface extending over said enclosure, said plurality of panels comprise a first edge-panel and a series of panels, some of which are also edge-panels, said first panel has at least one edge rested against means defining said enclosure and supported by support means secured thereto, the edges of this first panel which do not rest against said means comprise means for supporting a corresponding edge of the panel, of said series of panels, which is positioned adjacent to said first panel, all but one of the panels of this series of panels have means on at least one of their edges to support an adjacent panel and the edge panels of said series of panels have at least one of their edges supported by the support means secured to the means defining the enclosure; each panel which is provided with support means along two adjacent edges also comprises means for receiving a strut, these means being formed in a corner defined by said adjacent edges.